The subject invention relates to apparatus for moistening a sheet of paper. More particularly, it relates to apparatus for moistening a form sheet which has a remoistenable glue applied to selected areas, as the form sheet is folded and sealed to prepare a self-mailer.
Self mailers, that is form sheets on which may be printed address information and message information and then folded and sealed to form a mail piece are well known. U.S. Pat. No. 3,995,808; to: Kehoe; for: UNIT CONTAINING VARIABLE MESSAGES; issued: Dec. 7, 1976 discloses a form sheet which may be used to prepare a self-mailer. The self-mailer of Kehoe may be sealed by moistening remoistenable glue applied around the edges of the form sheet.
Various systems for applying moisture to remoistenable glues are known. U.S. Pat. No. 2,717,574; to: Bore; for: GUMMED STRIP MOISTENING DEVICE; issued: Sept. 13, 1955 shows a moistening device where a gum strip passes over the upper part of an array of closely spaced parallel plates having their lower portions immersed in a reservoir of water. Capillary action between the plates carries water to the strip. U.S. Pat. No. 4,799,989; to: Marzullo; for: DOCUMENT MOISTENING DEVICE; issued: Jan. 24, 1989 shows an apparatus where a pivotable hammer urges a document against a moistened wick.
Other techniques for sealing form sheets are also known. U.S. Pat. No. 4,701,233; to: Beck et al; for: METHOD FOR FOLDING AND SEALING SHEETS; issued: Oct. 20, 1987 discloses an apparatus for folding and sealing documents produced by a facsimile system. As the documents are output from the facsimile system, they are folded and sealed by the application of glue dots to selected spots along the edges of the documents.
While such apparatus may have been satisfactory for their intended application, they have proven to have numerous disadvantages. Difficulties have arisen in maintaining a proper level of fluid in moistening apparatus as they are operated over long periods of time, and such apparatus have tended to become clogged by the transfer of adhesive from the document to the apparatus. Glue dispensing systems have proven to be expensive and complicated, generally requiring pumps to move viscous glues.
Accordingly, it is an object of the subject invention to provide a simple and economical moistening apparatus which resists clogging.
It is another object of the subject invention to provide such an apparatus which is operable over a range of fluid levels maintained in the supply system.